The present invention relates, in general, to seal arrangements and more particularly relates to seal arrangements useful in fluid motors as stator seal means useful in connection with stator seals for use with fluid actuated rotary motor arrangements adapted to provide reciprocatory rotary motion through a portion of a cycle. Rotary motion devices have numerous applications including opening and closing valves, toggling and providing other services where push/pull or reciprocatory movements are involved.
In general actuators of the type previously described include a housing with head walls, where the housing defines a chamber in which a shaft is connected to a vane to provide rotary response to a shaft which carries the vane and the shaft extends through the housing and out through the housing head. The vane member is cycled to and fro by the pressure of a fluid emitted to one side and then the other side of the vane within the chamber and the concurrent exhaust of fluid at the opposite side. Stator arrangements are generally provided in such devices to define one side of the chamber and, in some instances, multi stators are provided in order to define more than one chamber. Previous vane type rotary type actuators have generally been distinguished by the fact that they require frequent servicing and replacement of seals due to wear.
Additionally effective sealing has been a problem in such devices and fluid leakage around the seals has been particularly troublesome.
In general the prior art arrangements have generally provided seal arrangements for pneumatic systems where the leakage rate has been in the the order of 0.1 standard cubic feet per minute and in some instances considerably higher leak rates are common.
Considerable improvment has been achieved by arrangements shown in U.S. Pat. No. 4,475,738 in U.S. Pat. No. 4,474,105 and the present invention provides some improvment even in the operation of devices provided by the aforenoted Patents.
Additional prior art arrangements are shown in the U.S. Pat. No. 3,128,679 wherein a rotary device is shown with a housing defining a chamber, a vane and seal arrangement which includes internal seal from around the inner end of a shaft bore where the shaft passes through the head of the device. A somewhat similar arrangement is shown in U.S. Pat. No. 2,806,451 and U.S. Pat. No. 3,682,050 when both arrangments two piece vane seals are shown. Additional arrangements for vane type actuators are shown in U.S. Pat. No. 3,131,610 where a seal arrangement is provided around the entire pheriphery of a vane. In U.S. Pat. No. 3,179,020 where split vane is provided.
No prior seal arrangement known for an actuator device where a ring seal is provided including a tab arrangement to extend radially outwardly from the ring to engage a seal member of an associated stator to prevent leakage therebetween.